CUTTING METHOD, PRODUCTION METHOD, CONTROL DEVICE AND GAS CUTTING DEVICE

Abstract

SOLUTION: There is provided a cutting method for a metal material made from a metal element or an alloy containing a metal element as a main component. The cutting method comprises a step of cutting a metal material by melting a cutting region of the metal material in a state where a viscosity reducing substance that reduces viscosity of a molten material of the metal element is supplied onto a surface of the cutting region of the metal material. The metal element may be iron. A carbon content of iron or iron alloy contained in the metal material may be 0.45% by mass or less.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a cutting method, a production method, a control device and a gas cutting device. [Background technology]

[0002] Patent Document 1 discloses a gas cutting device that uses gas to cut a material to be cut. Non-Patent Document 1 discloses the results of measuring the viscosity of a molten iron alloy when the carbon and / or silicon content in the molten iron alloy is changed. Non-Patent Document 2 discloses an iron-carbon equilibrium diagram. Non-Patent Document 3 discloses that for various pure metals and alloys, the viscosity of molten metal near the melting point is proportional to the 1 / 2 power of the melting point. [Prior art document] [Patent documents] [Patent Document 1] JP 2018-167299 A [Non-patent literature] [Non-Patent Document 1] Yasuji Kawai, Masayoshi Tsuji, Michitaka Kanemoto, "Viscosity of Molten Fe-C-Si Alloys", Iron and Steel, 1974, No. 60, No. 1, pp. 38-44 [Non-Patent Document 2] Ryohei Tanaka, "On the Recent Iron-Carbon Equilibrium Phase Diagram," Iron and Steel, 1967, 53rd year, No. 14, pp. 35-54 [Non-Patent Document 3] Masazumi Hirai, "Equation for Estimating Viscosity of Molten Alloys", Tetsu-to-Haganen, 1992, No. 78, No. 3, pp. 399-406 Summary of the Invention [Means for solving the problem]

[0003] In a first aspect of the present invention, a cutting method is provided. The cutting method is used, for example, to cut a metal material made of a metal element or an alloy mainly composed of a metal element. The cutting method includes, for example, a step of melting a cutting region of the metal material in a state where a viscosity reducing substance that reduces the viscosity of a melt of the metal element is supplied to a surface of the cutting region of the metal material, thereby cutting the metal material.

[0004] In the above cutting method, the step of cutting the metal material may include a step of supplying a viscosity reducing substance to a surface of the metal material such that a ratio of the mass of the viscosity reducing substance supplied to the cutting region to the mass of the metal material arranged in the cutting region is 0.05% by mass or more and 10% by mass or less. In the above cutting method, the step of cutting the metal material may include a step of supplying a viscosity reducing substance to a surface of the metal material such that a ratio of the mass of the viscosity reducing substance supplied to the cutting region to the mass of the metal material arranged in the cutting region is 0.1% by mass or more and 5% by mass or less. In the above cutting method, the viscosity reducing substance may include at least one element of carbon, silicon, and aluminum.

[0005] In the above cutting method, the step of cutting the metal material may include a step of preparing an object to be cut having a viscosity reducing substance disposed on a surface of a cutting region of the metal material. In the above cutting method, the step of cutting the metal material may include a step of heating the cutting region of the metal material and the viscosity reducing substance disposed on the cutting region to melt the cutting region of the metal material. In the above cutting method, the object to be cut may have a viscosity adjusting material disposed on a surface of the cutting region of the metal material, the viscosity reducing substance and a binder. In the above cutting method, the viscosity reducing substance may include a powder-like, granular, rod-like, fibrous or film-like carbon material.

[0006] In the above cutting method, the step of cutting the metal material may include a step of (i) heating the cutting region of the metal material and supplying an oxygen-containing gas to the heated metal material to melt the cutting region of the metal material. In the above cutting method, the step of cutting the metal material may include a step of (ii) heating the cutting region of the metal material with an electric arc or a plasma arc to melt the cutting region of the metal material. In the above cutting method, the step of cutting the metal material may include a step of (iii) heating the cutting region of the metal material with a laser beam to melt the cutting region of the metal material.

[0007] The above cutting method may include a step of melting the metallic material such that the mass of the viscosity reducing substance contained in the molten metallic material is 0.45% by mass or more and 10% by mass or less of the mass of the molten metallic material. In the above cutting method, the metallic element may be iron. In the above cutting method, the carbon content of the iron or iron alloy contained in the metallic material may be 0.45% by mass or less.

[0008] In a second aspect of the present invention, a production method is provided. The production method is, for example, a method for producing a metal member. The production method includes, for example, a step of cutting a metal material to produce a metal member. In the production method, the step of producing the metal member includes, for example, a step of cutting the metal material by the cutting method according to the first aspect described above.

[0009] In a third aspect of the present invention, a control device is provided. The control device controls, for example, a gas cutting device. In the control device, the gas cutting device includes, for example, a support unit that supports the workpiece. The gas cutting device includes, for example, a jet unit that jets fuel gas and oxygen-containing gas. The gas cutting device includes, for example, a distance adjustment unit that adjusts the relative distance between the jet unit and the surface of the workpiece. The gas cutting device includes, for example, a drive unit that moves the jet unit along the surface of the workpiece. In the control device, the workpiece has, for example, a metal material made of iron or an iron alloy mainly composed of iron. The workpiece has, for example, a viscosity reducing substance that is arranged on the surface of the cutting region of the metal material and reduces the viscosity of molten iron. The control device includes, for example, a control unit that determines cutting conditions including at least one of (i) a flow rate of fuel gas supplied to the jet unit, (ii) a flow rate of oxygen-containing gas supplied to the jet unit, (iii) a relative distance between the jet unit and the surface of the workpiece, and (iv) a moving speed of the jet unit based on the amount of the viscosity reducing substance arranged on the cutting region of the metal material.

[0010] In the above control device, the control unit may have a first determination unit that determines cutting conditions based on a ratio of the mass of the viscosity reducing substance disposed in the cutting region to the mass of the metal material disposed in the cutting region. In the above control device, the workpiece may have a first surface and a second surface disposed on the opposite side of the first surface. In the above control device, the ejection unit may be disposed so as to be located on the first surface side of the workpiece when the support unit supports the workpiece. In the above control device, the gas cutting device may include an imaging unit that images at least a part of the second surface of the workpiece. In the above control device, the control unit may have a second determination unit that (i) analyzes an image of the second surface of the workpiece captured by the imaging unit to estimate a flow state of the molten metal material, and (ii) determines cutting conditions based on the estimated flow state of the molten material.

[0011] In a fourth aspect of the present invention, a gas cutting device is provided. The gas cutting device includes, for example, a support part for supporting an object to be cut. The gas cutting device includes, for example, a jet part for jetting a fuel gas and an oxygen-containing gas. The gas cutting device includes, for example, a distance adjustment part for adjusting a relative distance between the jet part and a surface of the object to be cut. The gas cutting device includes, for example, a drive part for moving the jet part along the surface of the object to be cut. The gas cutting device includes, for example, the control device according to the third aspect described above. In the gas cutting device, the object to be cut includes, for example, a metal material made of iron or an iron alloy mainly composed of iron. The object to be cut includes, for example, a viscosity reducing substance arranged on the surface of the cutting region of the metal material and reducing the viscosity of the molten iron.

[0012] In a fifth aspect of the present invention, a program is provided. The program may be a program for causing a computer to function as the control device according to the third embodiment. A computer-readable medium storing the program may be provided. The computer-readable medium may be a non-transitory computer-readable medium. The computer-readable medium may be a computer-readable recording medium.

[0013] The above summary of the invention does not list all of the necessary features of the present invention. Also, subcombinations of these features may also be inventions. [Brief description of the drawings]

[0014] [Figure 1] 1 shows an example of a system configuration of a gas cutting system 100. [Diagram 2] 1 is a schematic diagram showing an example of a cross-sectional view of an object 10 to be cut. [Diagram 3] 1 is a schematic diagram showing an example of a top view of an object 10 to be cut. [Figure 4] 2A and 2B are schematic diagrams showing other examples of cross-sectional views of the object 10 to be cut. [Diagram 5] 2 is a schematic diagram showing yet another example of a cross-sectional view of the object 10 to be cut. [Figure 6] 2 illustrates an example of the internal configuration of the controller 180. [Figure 7] An example of a cutting method using the gas cutting system 100 is shown generally. [Figure 8] An example of the system configuration of a computer 3000 is shown in schematic form. [Figure 9] In Example 1, a state in which slag is discharged from the back surface of the workpiece is shown. [Figure 10] In Comparative Example 1, the state in which slag is discharged from the back surface of the workpiece is shown. [Figure 11] In Reference Example 1, the state in which slag is discharged from the back surface of the workpiece is shown. [Figure 12] This indicates the volume of sludge adhering to the back surface of the cut object. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] The present invention will be described below through the embodiments of the invention, but the following embodiments do not limit the invention according to the claims. In addition, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention. In the drawings, the same reference numbers are used for the same or similar parts, and duplicate explanations may be omitted.

[0016] An example of the gas cutting system 100 will be described in detail with reference to Figures 1, 2, and 3. Figure 1 shows an example of a system configuration of the gas cutting system 100. Figure 2 shows an example of a cross-sectional view of the workpiece 10. Figure 3 shows an example of a top view of the workpiece 10. In this embodiment, the gas cutting system 100 will be described in detail with reference to an example in which the gas cutting system 100 (i) cuts the workpiece 10 containing iron or an iron alloy by a gas cutting method (sometimes referred to as a gas fusing method), and (ii) produces members 32 and 34.

[0017] [Outline of the gas cutting system 100] 1, in this embodiment, the gas cutting system 100 includes, for example, a gas burner 110. In this embodiment, the gas burner 110 has a cutting tip 112. In this embodiment, the gas cutting system 100 includes, for example, a carriage 120. In this embodiment, the carriage 120 has a burner support section 122 and a transport section 124. In this embodiment, the gas cutting system 100 includes, for example, a stand 130. In this embodiment, the stand 130 has a table 132, a table 134 that supports the workpiece 10, a support column 136, and a rail 138.

[0018] In this embodiment, the gas cutting system 100 includes, for example, an oxygen supply system 140. In this embodiment, the oxygen supply system 140 includes a pipe 142, an oxygen-containing gas source 144, a pressure gauge 146, a mass flow controller 147, and a valve 148. In this embodiment, the gas cutting system 100 includes, for example, a fuel supply system 150. In this embodiment, the fuel supply system 150 includes, for example, a pipe 152, a fuel gas source 154, a pressure gauge 156, a mass flow controller 157, and a valve 158.

[0019] In this embodiment, the gas cutting system 100 includes, for example, one or more cameras 160. In this embodiment, the gas cutting system 100 includes, for example, one or more input / output devices 170. In this embodiment, the gas cutting system 100 includes, for example, a controller 180.

[0020] [Overview of the workpiece 10] 2 and 3, in this embodiment, the object 10 includes a steel plate 12 and a carbon supply layer 14. In this embodiment, the carbon supply layer 14 includes a solid carbon source 22 and a binder resin 24. In this embodiment, a cutting region 200 is set in a part of the object 10. A preheating region 300 is set in a part of the cutting region 200.

[0021] In this embodiment, the steel plate 12 may be a steel material made of iron or an alloy mainly composed of iron. The above alloy may contain at least one of carbon, silicon, manganese, phosphorus, sulfur, nickel, chromium, molybdenum, and boron in addition to iron. The steel plate 12 may contain impurities contained in the raw materials of the steel plate 12 and / or impurities (sometimes referred to as inevitable impurities) mixed in during the manufacturing process.

[0022] Examples of materials for the steel plate 12 include (i) pure iron, (ii) iron-carbon alloy, (iii) alloy containing metal elements other than carbon and having iron as the main component, and (iv) alloy containing carbon and metal elements other than carbon and having iron as the main component. When the material for the steel plate 12 is pure iron, the carbon content of the alloy may be less than 0.02 mass% or less than 0.01 mass%. When the material for the steel plate 12 is an alloy containing carbon, the carbon content of the alloy may be 0.02 mass% or more and 2.06 mass% or less.

[0023] When the material of the steel plate 12 is an iron-carbon alloy, the lower limit of the carbon content of the alloy may be 0.05 mass% or less. When the material of the steel plate 12 is an iron-carbon alloy, the upper limit of the carbon content of the alloy may be 1 mass% or less, 0.5 mass% or less, 0.45 mass% or less, 0.3 mass% or less, 0.25 mass% or less, or less than 0.25 mass%. The smaller the carbon content of the steel plate 12, the more pronounced the effect of carbon being supplied from the carbon supply layer 14.

[0024] In this embodiment, the steel plate 12 has a plate-like shape and has two substantially parallel surfaces. In this embodiment, of the two surfaces, the surface facing the cutting tip 112 of the gas burner 110 when the workpiece 10 is cut is referred to as FS. On the other hand, the surface disposed on the opposite side to FS is referred to as BS.

[0025] In this embodiment, the carbon supply layer 14 is disposed on one surface (sometimes referred to as FS) of the steel plate 12. The carbon supply layer 14 is produced, for example, by (i) mixing a solid carbon source 22 and a binder resin 24 with a solvent to obtain a paste, applying the paste to the FS side surface of the steel plate 12, and (ii) drying the paste.

[0026] In this embodiment, the length of the carbon supply layer 14 in the y direction (sometimes referred to as the width Wa of the carbon supply layer 14) is greater than the length of the cutting region 200 in the y direction (sometimes referred to as the width Wc of the cutting region 200, the cutting width, etc.). The width Wc of the cutting region 200 is determined by, for example, the diameter of the flame ejected from the cutting nozzle 112.

[0027] In this embodiment, the length in the z direction of the carbon supply layer 14 (sometimes referred to as the thickness Ha of the carbon supply layer 14) is smaller than the length in the z direction of the steel plate 12 (sometimes referred to as the thickness Hm of the steel plate 12). In one embodiment, the thickness Ha of the carbon supply layer 14 is determined by the thickness Hm of the steel plate 12, the density of the steel plate 12, and the carbon content of the carbon supply layer 14. In another embodiment, the thickness Ha of the carbon supply layer 14 is determined by the thickness Hm of the steel plate 12, the density of the steel plate 12, the carbon content of the carbon supply layer 14, and the amount of ejected oxygen-containing gas.

[0028] For example, the thickness Ha of the carbon supply layer 14 is determined so that the mass of carbon contained in the molten steel plate 12 is 0.45 mass% or more and 10 mass% or less of the mass of the molten steel plate 12. The thickness Ha of the carbon supply layer 14 may be determined so that the mass of carbon contained in the molten steel plate 12 is 0.5 mass% or more and 7 mass% or less of the mass of the molten steel plate 12. The thickness Ha of the carbon supply layer 14 may be determined so that the mass of carbon contained in the molten steel plate 12 is 1.0 mass% or more and 6.5 mass% or less of the mass of the molten steel plate 12. The thickness Ha of the carbon supply layer 14 may be determined so that the mass of carbon contained in the molten steel plate 12 is 1.5 mass% or more and 6.25 mass% or less of the mass of the molten steel plate 12. The thickness Ha of the carbon supply layer 14 may be determined so that the mass of carbon contained in the molten steel sheet 12 is 2.0 mass % or more and 5.75 mass % or less of the mass of the molten steel sheet 12.

[0029] More specifically, the thickness Ha of the carbon supply layer 14 is determined so that the ratio of the mass of carbon contained in the carbon supply layer 14 arranged in the cutting region 200 to the mass of the steel plate 12 arranged in the cutting region 200 is 0.05 mass% or more and 10 mass% or less. As a result, the mass of carbon contained in the molten steel plate 12 (i.e., the sum of the mass of carbon contained in the steel plate 12 arranged in the cutting region 200 and the mass of carbon contained in the carbon supply layer 14 arranged in the cutting region 200) can be 0.45 mass% or more and 10 mass% or less of the mass of the molten steel plate 12.

[0030] The thickness Ha of the carbon supply layer 14 may be determined so that the ratio of the mass of carbon contained in the carbon supply layer 14 arranged in the cutting region 200 to the mass of the steel plate 12 arranged in the cutting region 200 is 0.1 mass% or more and 5 mass% or less. The thickness Ha of the carbon supply layer 14 may be determined so that the ratio of the mass of carbon contained in the carbon supply layer 14 arranged in the cutting region 200 to the mass of the steel plate 12 arranged in the cutting region 200 is 0.5 mass% or more and 4.5 mass% or less.

[0031] In this embodiment, the length of the carbon supply layer 14 in the x direction (sometimes referred to as the length La of the carbon supply layer 14) is smaller than the length of the steel plate 12 in the x direction (sometimes referred to as the length Lm of the steel plate 12). This allows a preheating region 300 in which the carbon supply layer 14 is not disposed to be formed in a part of the cutting region 200. In the drawing, Lc indicates the length of the cutting region 200.

[0032] In this embodiment, the solid carbon source 22 includes, for example, a powder-like, granular (sometimes referred to as chip-like), rod-like (sometimes referred to as needle-like, wire-like, whisker-like, etc.), fibrous, or film-like (sometimes referred to as foil-like, sheet-like, tape-like, etc.) carbon material. Various carbonized substances can be used as the carbon material. Examples of the carbon material include charcoal, bamboo charcoal, coconut shell charcoal, coal, briquettes, activated carbon, petroleum solid residue, pitch, coke, amorphous carbon (soot), carbon black, graphite, graphene, carbon nanotubes, resin, natural rubber, and synthetic rubber. Examples of fibrous carbon materials (including bicarbonates called carbon fibers) include carbonized polymer fibers, carbon nanofibers, graphite fibers, and graphite nanofibers.

[0033] In this embodiment, the binder resin 24 binds the solid carbon sources 22 together. The binder resin 24 may fix the solid carbon sources 22 to the surface of the steel plate 12. The binder resin 24 may be a cured organic polymer, any of various adhesives, or any of various pressure-sensitive adhesives. Examples of the binder resin 24 include natural polymers and organic polymers. Examples of the natural polymers include gelatin, starch, sucrose, cellulose, rosin, and glue. Examples of the organic polymers include acrylic resin, epoxy resin, phenol resin, vinyl chloride resin, polyvinyl acetate, and polyvinyl alcohol. The binder resin 24 may be a thermosetting resin or an ultraviolet-curing resin. This can shorten the production period of the carbon supply layer 14.

[0034] According to this embodiment, the carbon supply layer 14 is disposed on the surface of the steel plate 12. Therefore, when the gas cutting system 100 heats the cutting region 200 of the object 10 to cut the object 10, the steel plate 12 disposed in the cutting region 200 melts in a state in which carbon is supplied from the carbon supply layer 14 to the surface of the steel plate 12. This increases the carbon concentration of the molten steel plate 12 compared to when the steel plate 12 is simply melted (i.e., compared to when the object 10 does not have the carbon supply layer 14).

[0035] As shown in Non-Patent Document 1, it is known that in the region where the carbon content of the molten iron or iron alloy is equal to or less than the eutectic carbon amount (about 4.3% by mass), the viscosity of the molten iron or iron alloy decreases as the carbon content of the molten iron or iron alloy increases. Also, as shown in Non-Patent Document 2, in an iron-carbon alloy, in the region where the carbon content of the alloy is equal to or less than the eutectic carbon amount (about 4.3% by mass), the melting point of the alloy gradually decreases. On the other hand, in the region where the carbon content of the molten iron or iron alloy exceeds the eutectic carbon amount (about 4.3% by mass), the melting point of the alloy gradually increases.

[0036] According to Non-Patent Document 2, for example, the melting point of an iron-carbon alloy with a carbon content of 0.5% by mass is approximately the same as that of the alloy with a carbon content of 7.0% by mass. The melting point of an iron-carbon alloy with a carbon content of 1.0% by mass is approximately the same as that of the alloy with a carbon content of 6.5% by mass. The melting point of an iron-carbon alloy with a carbon content of 1.5% by mass is approximately the same as that of the alloy with a carbon content of 6.25% by mass. In addition, the melting point of an iron-carbon alloy with a carbon content of 2.0% by mass is approximately the same as that of the alloy with a carbon content of 5.75% by mass.

[0037] Furthermore, as shown in Non-Patent Document 3, as the melting points of various pure metals and alloys decrease, the viscosity of the molten metal near the melting point also decreases. Considering the common technical knowledge disclosed in Non-Patent Document 3, a person skilled in the art who has read Non-Patent Document 2 can understand that in the iron-carbon alloy shown in Non-Patent Document 2, in a region in which the carbon content of the alloy is equal to or less than the eutectic carbon amount (approximately 4.3 mass%), the melting point of the alloy gradually decreases and the viscosity of the molten alloy decreases.

[0038] Based on technical common sense, for example as described in Non-Patent Documents 1-3, the inventors came up with the idea that when cutting steel sheet 12 by heating and melting a portion of steel sheet 12, by adjusting the carbon content of the molten steel sheet 12 to be within a specific numerical range (for example, within a specific numerical range including the eutectic carbon amount), it is possible to reduce the viscosity of the molten steel sheet 12 compared to when the carbon content of the molten steel sheet 12 is outside the above numerical range.

[0039] In cutting methods such as gas cutting, arc cutting, and laser cutting, a part of a metal material is melted by various principles, and the melted metal material is blown away by an air current to cut the metal material. Depending on the cutting conditions, slag of the melted material may adhere to the cut metal material. In particular, as the thickness of the metal material increases, it becomes difficult to suppress the amount of slag that adheres.

[0040] Therefore, the inventors have come up with the idea of ​​melting a cut region of a metal material while a viscosity-reducing substance that reduces the viscosity of the molten metal constituting the metal material is supplied to the surface of the cut region of the metal material. According to the above method, the viscosity of the molten metal material is reduced compared to when the viscosity-reducing substance is not supplied during melting of the metal material. This makes it easier for the molten metal material to be blown away by the air flow. As a result, the amount of slag adhering to the cut metal material can be reduced.

[0041] It has been known that when cutting low-carbon steel (carbon steel with a carbon content of less than 0.25% by mass) by arc cutting, for example, carbon from the carbon electrode gets mixed into the molten low-carbon steel. However, the increase in carbon is a small amount, less than 0.05%, and the idea of ​​actively mixing carbon into the molten steel to suppress slag adhesion or improve slag removability has not been known.

[0042] In contrast, according to this embodiment, the thickness Ha of the carbon supply layer 14 is determined so that the mass of carbon contained in the molten steel plate 12 is, for example, 0.45 mass% or more and 10 mass% or less of the mass of the molten steel plate 12. The ratio of the mass of carbon contained in the molten steel plate 12 to the mass of the molten steel plate 12 is preferably 0.5 mass% or more and 7 mass% or less, more preferably 1.0 mass% or more and 6.5 mass% or less, even more preferably 1.5 mass% or more and 6.25 mass% or less, and even more preferably 2.0 mass% or more and 5.75 mass% or less.

[0043] As described above, the viscosity of the molten iron or iron alloy varies depending on the carbon content of the molten iron or iron alloy. When the carbon content of the molten steel sheet 12 is 0.45 mass% or more and 10 mass% or less of the mass of the molten steel sheet 12, the viscosity of the molten steel sheet 12 is smaller than when the carbon content of the molten steel sheet 12 is about 0.2 to 0.3 mass%. This makes it easier for the molten steel sheet 12 to be discharged from the BS side of the steel sheet 12 when the steel sheet 12 is melt-cut. As a result, it is possible to reduce the amount of slag adhering to the BS side of the steel sheet 12 and to reduce the flow rate of the oxygen-containing gas for blowing off the molten steel sheet 12.

[0044] The above concept is not limited to cutting the steel plate 12. In general, when a solute that dissolves only in the liquid phase and not in the solid phase is added to a solvent, the freezing point of the solution containing the solute and the solvent is lowered, and the freezing point of the solution becomes lower than the freezing point of the pure solvent. The above phenomenon is called freezing point depression. Freezing point depression can also be observed in melts of various metals or alloys. Therefore, the matters described in relation to cutting the steel plate 12 can also be applied to cutting various metals or alloys.

[0045] For example, in the case of cutting a metal material by melting a part of the metal material by various principles and blowing away the molten metal material with an air flow, it is possible to melt the cutting area of ​​the metal material in a state where a substance that lowers the freezing point of the pure metal or alloy (sometimes simply called metal) that is the main component of the metal material is supplied to the surface of the cutting area of ​​the metal material. Examples of the main component of the metal material include a component that is more than 50% by mass of the metal material, a component that is more than 75% by mass of the metal material, a component that is more than 80% by mass of the metal material, a component that is more than 90% by mass of the metal material, and a component that is more than 95% by mass of the metal material. The above-mentioned method can also be applied to the case of cutting a member containing the metal material by cutting a part of the metal material.

[0046] [Details of each part of the gas cutting system 100] In this embodiment, the gas cutting system 100 cuts the workpiece 10 by a gas cutting method. For example, the gas cutting system 100 cuts a cutting area 200 set in a part of the workpiece 10. For example, in a state in which carbon contained in the carbon supply layer 14 is supplied to the surface of the cutting area 200 of the steel plate 12, the cutting area of ​​the steel plate 12 is melted to cut the steel plate 12. As a result, the member 32 and the member 34 are produced.

[0047] In this embodiment, the gas burner 110 generates a flame for heating the workpiece 10. More specifically, the gas burner 110 ejects an oxygen-containing gas supplied from an oxygen supply system 140 and a fuel gas supplied from a fuel supply system 150 from a cutting tip 112. The gas burner 110 ignites the fuel gas ejected from the cutting tip 112 using an ignition device (not shown).

[0048] The cutting tip 112 ejects an oxygen-containing gas supplied from an oxygen supply system 140 and a fuel gas supplied from a fuel supply system 150. Examples of the oxygen-containing gas include (i) high-purity oxygen gas and (ii) a mixture of oxygen gas and an inert gas. Examples of the inert gas include nitrogen gas, helium gas, and argon gas. Examples of the fuel gas include hydrogen gas and a hydrocarbon gas. Examples of the hydrocarbon gas include natural gas and LP gas.

[0049] The cutting tip 112 may have multiple nozzles (not shown). For example, the cutting tip 112 may have one or more nozzles for ejecting an oxygen-containing gas and one or more nozzles for ejecting a fuel gas. The cutting tip 112 may have one or more nozzles for ejecting an oxygen gas, one or more nozzles for ejecting an inert gas, and one or more nozzles for ejecting a fuel gas.

[0050] In one embodiment, a single nozzle is used for a single type of gas. In this case, for example, oxygen gas for preheating and oxygen gas for cutting are ejected from the same nozzle. In another embodiment, multiple nozzles are used for a single type of gas. In this case, for example, the cutting nozzle 112 has one or more nozzles for ejecting oxygen gas for preheating and one or more nozzles for ejecting oxygen gas for cutting. The cutting nozzle 112 may further have one or more nozzles for ejecting oxygen gas for a curtain.

[0051] In this embodiment, the carriage 120 adjusts the relative position between the cutting tip 112 and the object 10. Specifically, when two directions parallel to the horizontal direction and perpendicular to each other are defined as the x direction and the y direction, and the vertical direction is defined as the z direction, the carriage 120 adjusts at least one of (i) the distance between the representative point of the cutting tip 112 and the representative point of the object 10 in the x direction, (ii) the distance between the representative point of the cutting tip 112 and the representative point of the object 10 in the y direction, (iii) the distance between the representative point of the cutting tip 112 and the representative point of the object 10 in the z direction, and (iv) the angle between the ejection direction of gas or flame from the cutting tip 112 and the vertical direction. The carriage 120 may adjust the relative position between the cutting tip 112 and the object 10 in accordance with a control signal from the controller 180.

[0052] The representative point of the cutting tip 112 may be the tip of the cutting tip 112. Examples of the representative point of the workpiece 10 include the start position on the FS side of the cutting area of ​​the steel plate 12 and the start position on the FS side of the cutting area of ​​the carbon supply layer 14. The representative point of the cutting tip 112 and the representative point of the workpiece 10 may be determined so that the tip distance is the shortest when the workpiece 10 and the cutting tip 112 are placed at the cutting start position.

[0053] In this embodiment, the cutting tip 112 is disposed at the tip of the gas burner 110, and ejects various gases and / or flames toward the workpiece 10. The cutting tip 112 is disposed so as to be located on the FS side of the workpiece 10 when the stand 130 supports the workpiece 10.

[0054] In this embodiment, the burner support part 122 supports the gas burner 110. The burner support part 122 adjusts, for example, the relative distance between the cutting tip 112 of the gas burner 110 and the surface of the workpiece 10. More specifically, the burner support part 122 adjusts, for example, the distance in the z direction between a representative point of the cutting tip 112 and a representative point of the workpiece 10 (sometimes referred to as tip distance, tip height, etc.). In addition, the burner support part 122 adjusts, for example, the angle between the ejection direction of gas or flame from the cutting tip 112 and the vertical direction.

[0055] In one embodiment, the burner support 122 adjusts at least one of the nozzle distance and the angle according to a control signal from the controller 180. In another embodiment, the burner support 122 is manually operated by a user to adjust at least one of the nozzle distance and the angle.

[0056] In this embodiment, the transport unit 124 transports the gas burner 110 supported by the burner support unit 122. For example, the transport unit 124 moves along a rail 138 installed on the stand 130. In this embodiment, the rail 138 extends along the x direction, and the workpiece 10 and the rail 138 are installed approximately parallel to the horizontal direction. This allows the transport unit 124 to move the gas burner 110 along the surface of the workpiece 10.

[0057] In one embodiment, the transport unit 124 moves the gas burner 110 according to a control signal from the controller 180. For example, the transport unit 124 moves the gas burner 110 at a speed indicated by a control signal from the controller 180. In another embodiment, the position of the gas burner 110 in the x-direction can be adjusted by a user manually operating the transport unit 124.

[0058] In this embodiment, the stand 130 supports the object 10. In this embodiment, the stand 130 supports the dolly 120. The stand 130 supports the dolly 120 such that the dolly 120 is positioned above the object 10.

[0059] In this embodiment, the table 132 supports the object 10. The table 132 supports the object 10, for example, so that the FS of the object 10 is approximately parallel to the horizontal direction. In this embodiment, the table 134 supports the cart 120. The table 134 supports the cart 120, for example, so that the movement direction of the cart 120 is approximately parallel to the horizontal direction.

[0060] In this embodiment, the support pillar 136 supports the table 132 and the table 134. The support pillar 136 supports the table 132 and the table 134, for example, so that the table 134 is disposed above the table 132. This allows the cutting tip 112 of the gas burner 110 to be disposed on the FS side of the object 10 when the object 10 is disposed at a predetermined position on the table 132.

[0061] In this embodiment, the rail 138 is used as a track for the carriage 120. The rail 138 is disposed on the table 134 such that the extension direction of the rail 138 is approximately parallel to the horizontal direction. This allows the carriage 120 to move the cutting tip 112 along the surface of the workpiece 10.

[0062] In this embodiment, an oxygen supply system 140 supplies oxygen-containing gas to the gas burner 110. In this embodiment, piping 142 transports oxygen-containing gas from an oxygen-containing gas source 144 to the gas burner 110.

[0063] In this embodiment, the oxygen-containing gas source 144 supplies an oxygen-containing gas to the pipe 142. The oxygen-containing gas source 144 may have a gas storage facility such as a gas cylinder or a gas tank. The oxygen-containing gas source 144 may have an oxygen gas storage facility for storing high-purity oxygen gas, an inert gas storage facility for storing an inert gas, and a mixing facility for mixing the oxygen gas and the inert gas.

[0064] In this embodiment, the pressure gauge 146 measures the pressure of the gas inside the pipe 142. The pressure gauge 146 outputs information indicating the measurement result to the controller 180. In this embodiment, the mass flow controller 147 adjusts the flow rate of the oxygen-containing gas supplied from the oxygen-containing gas source 144 to the gas burner 110. The mass flow controller 147 may adjust the flow rate of the oxygen-containing gas according to a control signal from the controller 180.

[0065] In this embodiment, the valve 148 switches the communication state of the pipe 142. Specifically, the valve 148 switches between a state in which oxygen-containing gas can be transported from the oxygen-containing gas source 144 to the gas burner 110 and a state in which oxygen-containing gas is not transported from the oxygen-containing gas source 144 to the gas burner 110. The valve 148 switches the communication state of the pipe 142 in accordance with a control signal from the controller 180. The valve 148 may adjust the opening degree of the valve 148 in accordance with the control signal from the controller 180.

[0066] In this embodiment, a fuel supply system 150 supplies fuel gas to the gas burner 110. In this embodiment, piping 152 transports the fuel gas from the fuel supply system 150 to the gas burner 110.

[0067] In this embodiment, the fuel gas source 154 supplies fuel gas to the pipe 152. The fuel gas source 154 may include a gas storage facility such as a gas cylinder or a gas tank. The fuel gas source 154 may include a first fuel gas storage facility for storing a first type of fuel gas, a second fuel gas storage facility for storing a second type of fuel gas, and a mixing facility for mixing the first type of fuel gas and the second type of fuel gas.

[0068] In this embodiment, the pressure gauge 156 measures the pressure of the gas inside the pipe 152. The pressure gauge 156 outputs information indicating the measurement result to the controller 180. In this embodiment, the mass flow controller 157 adjusts the flow rate of the fuel gas supplied from the fuel gas source 154 to the gas burner 110. The mass flow controller 157 may adjust the flow rate of the fuel gas in accordance with a control signal from the controller 180.

[0069] In this embodiment, the camera 160 captures an image of the exterior of the object 10. For example, the camera 160 captures an image of at least a part of the BS of the object 10. When the gas cutting system 100 includes a plurality of cameras 160, some of the cameras 160 may capture an image of the BS side of the object 10, and the remaining cameras 160 may capture an image of the FS side of the object 10.

[0070] This allows an image to be captured of the molten material of the object 10 being discharged from the BS side of the object 10. Also, an image to be captured of slag of the molten material of the object 10 adhering to the BS side of the object 10. The camera 160 outputs image data of the captured image to the controller 180. The image may be a still image or a moving image.

[0071] In this embodiment, the input / output device 170 functions as a user interface between the user and the gas cutting system 100. In one embodiment, the input / output device 170 accepts input from the user. The input / output device 170 may include an input device such as a keyboard, a pointing device, a touch panel, a voice recognition device, or a gesture recognition device. In another embodiment, the input / output device 170 outputs various information to the user. The input / output device 170 may include an output device such as a display, a projector, or a speaker.

[0072] In this embodiment, the controller 180 controls the gas cutting system 100. For example, the controller 180 determines cutting conditions including at least one of (i) a flow rate of fuel gas supplied to the gas burner 110, (ii) a flow rate of oxygen-containing gas supplied to the gas burner 110, (iii) a relative distance between the gas burner 110 and the surface of the workpiece 10, and (iv) a moving speed of the gas burner 110.

[0073] In one embodiment, the controller 180 determines the above cutting conditions based on the amount of the solid carbon source 22 disposed in the cutting region 200. In another embodiment, the controller 180 determines the above cutting conditions based on information input by a user to the input / output device 170. In this case, the user determines the cutting conditions based on, for example, the amount of the solid carbon source 22 disposed in the cutting region 200, and inputs information regarding the cutting conditions to the input / output device 170.

[0074] The controller 180 may control at least one of the burner support 122, the transfer unit 124, the oxygen supply system 140, and the fuel supply system 150 based on the determined cutting conditions. For example, the controller 180 may adjust setting values ​​of at least one of the burner support 122, the transfer unit 124, the oxygen supply system 140, and the fuel supply system 150 based on the determined cutting conditions. Details of the controller 180 will be described below.

[0075] The object 10 may be an example of the object to be cut. The FS may be an example of one of the first surface and the second surface. The BS may be an example of the other of the first surface and the second surface. The steel plate 12 may be an example of a metal material. The steel plate 12 arranged in the cutting region 200 may be an example of a cutting region of a metal material. The iron contained in the steel plate 12 may be an example of a metal element. The carbon contained in the steel plate 12 may be an example of a viscosity reducing substance. The carbon supply layer 14 may be an example of a viscosity reducing substance or a viscosity adjusting material. The carbon contained in the carbon supply layer 14 may be an example of a viscosity reducing substance. The mass of carbon contained in the carbon supply layer 14 arranged in the cutting region 200 may be an example of the amount of carbon supplied to the cutting region 200. The solid carbon source 22 may be an example of a viscosity reducing substance. The binder resin 24 may be an example of a binder. The member 32 may be an example of a metal member. The member 34 may be an example of a metal member.

[0076] The gas cutting system 100 may be an example of a gas cutting device. The gas burner 110 may be an example of a jetting unit. The cutting tip 112 may be an example of a jetting unit. Each of the one or more nozzles included in the cutting tip 112 may be an example of a jetting unit. The burner support unit 122 may be an example of a distance adjustment unit. The transport unit 124 may be an example of a drive unit. The stand 130 may be an example of a support unit. The table 132 may be an example of a support unit. The camera 160 may be an example of an imaging unit. The controller 180 may be an example of a control device or a control unit.

[0077] [An example of another embodiment] In this embodiment, the carbon supply method has been described in detail, taking as an example a case where the carbon supply layer 14 is disposed on the FS side surface of the steel plate 12. However, the carbon supply method is not limited to this embodiment. In other embodiments, the carbon supply layer 14 may be disposed on the BS side surface of the steel plate 12. The carbon supply layer 14 may be disposed on both the FS side and the BS side surfaces of the steel plate 12. In still another embodiment, the gas cutting system 100 may include a nozzle (not shown) for spraying a powdered or liquid carbon material, and the cutting region of the steel plate 12 may be melted while the powdered or liquid carbon material is sprayed onto the surface of the cutting region of the steel plate 12.

[0078] In this embodiment, the viscosity-reducing substance has been described in detail by taking as an example a case where a solid carbon source 22 is used as the viscosity-reducing substance. However, the viscosity-reducing substance is not limited to the solid carbon source 22. In other embodiments, the viscosity-reducing substance may be a substance other than gaseous oxygen molecules. The viscosity-reducing substance is preferably a substance that is a liquid or solid at 0°C, and is preferably a substance that is a liquid or solid at 25°C.

[0079] The viscosity reducing material may be an oxide. The viscosity reducing material may be a carbide. The viscosity reducing material may be a halide. The halide may be a fluoride or a chloride.

[0080] The viscosity reducing substance may include at least one selected from the group consisting of (i) oxides, carbides, or halides of the main constituent elements constituting the metallic material, (ii) minor components of the alloy constituting the metallic material, and (iii) oxides, carbides, or halides of minor components of the alloy constituting the metallic material. This reduces the viscosity of the molten metallic material to which the viscosity reducing substance has been added compared to the case in which the viscosity reducing substance is not added. Examples of the main constituent elements constituting the metallic material include the main components and / or minor components of the alloy constituting the metallic material.

[0081] For example, when a third component C is added to an alloy X having a metal element A as a main component and an element B as a subcomponent, the freezing point of the melt of the alloy X containing the third component C becomes lower than that of the melt of the alloy X not containing the third component C due to the freezing point depression. However, depending on the type and amount of the third component C, the viscosity of the melt of the alloy X containing the third component C may be higher than that of the melt of the alloy X not containing the third component C. For example, when Si is added to an Fe-C alloy, the melting point of the Fe-C alloy decreases due to the freezing point depression, but depending on the amount of Si added, the viscosity of the melt to which Si is added may be higher than that of the melt to which Si is not added.

[0082] Even in such a case, the viscosity of the molten material is reduced by adding a material containing carbon, which is a secondary component of the Fe-C alloy. Examples of the material containing carbon include the various carbon materials described above, limestone (CaCO 3 Limestone is used in the refining of iron ore to react with the iron silicate contained in the iron ore to separate the iron and silicate, and is highly effective in lowering the viscosity of the molten material.

[0083] The viscosity reducing substance may include at least one element selected from the group consisting of carbon, silicon, and aluminum. As described above, the viscosity reducing substance may be a carbonate, a silicon oxide, or an aluminum oxide. The viscosity reducing substance may be silicon carbide. The viscosity reducing substance may be a liquid natural polymer or an organic polymer. An example of a liquid natural polymer is tar.

[0084] In this embodiment, the details of the metal material are described by taking the case where a steel plate 12 is used as the metal material as an example. However, the metal material is not limited to the steel plate 12. The type of the cut object is not particularly limited as long as it is a material that can be cut by gas cutting, arc cutting (sometimes called plasma cutting), or laser cutting, and the viscosity of the molten material of the material can be adjusted by adjusting the concentration of an appropriate type of additive. In other embodiments, the metal material may be steel, stainless steel, aluminum, copper, or various alloys. The above alloys may be alloys mainly composed of iron, aluminum, or copper. Examples of cut objects other than metal materials include ceramics, resins, and composite materials of these and metal materials.

[0085] When the cutting method is gas cutting, the workpiece may be (i) steel, (ii) an alloy mainly composed of iron, or (iii) a member containing these. When the cutting method is arc cutting, the workpiece may be (i) steel, stainless steel, or aluminum, (ii) an alloy mainly composed of iron or aluminum, (iii) another conductive material, or (iv) a member containing these. When the cutting method is laser cutting, the workpiece may be (i) steel, stainless steel, aluminum, or copper, (ii) an alloy mainly composed of iron, aluminum, or copper, (iii) ceramics, (iv) resin, (v) composite material, or (iv) a member containing these.

[0086] When the metallic material is stainless steel, examples of the viscosity reducing substance include silicon, chromium, nickel, or oxides, carbides, or halides thereof. When the metallic material is aluminum, examples of the viscosity reducing substance include silicon, silicon oxide, aluminum oxide (sometimes called alumina), aluminum carbide, aluminum halide, etc. The viscosity reducing substance is preferably alumina or aluminum fluoride.

[0087] In this embodiment, an example of a method for cutting a metallic material has been described by taking as an example a case where the viscosity of a molten metallic material is adjusted by adjusting the concentration of a viscosity reducing substance in the molten metallic material. However, the method for cutting a metallic material is not limited to this embodiment. In other embodiments, the viscosity of the molten metallic material may be adjusted by adjusting the concentration of an oxide of the metal in the molten metallic material. For example, when the metallic material is iron or an iron alloy, the viscosity of the slag increases as the concentration of iron oxide in the slag increases. Therefore, a person skilled in the art who has come into contact with the description of this specification can understand that the same effect as that of this embodiment can be achieved by adjusting the composition of the slag so that the concentration of iron oxide in the slag falls within a specific numerical range.

[0088] Another example of the object 10 will be described in detail with reference to Fig. 4 and Fig. 5. Fig. 4 shows another example of the cross-section of the object 10. Fig. 5 shows yet another example of the cross-section of the object 10.

[0089] 4, the object 10 is different from the object 10 described with reference to FIGS. 2 and 3 in that the carbon supply layer 14 includes a resin layer 42 and an adhesive layer 44. With respect to features other than the above difference, the object 10 in FIG. 4 may have the same configuration as the object 10 described with reference to FIGS. 2 and 3.

[0090] In this embodiment, the resin layer 42 includes a solid carbon source 22 and a binder resin 24. The resin layer 42 is produced, for example, by (i) mixing the solid carbon source 22 and the binder resin 24 with a solvent to obtain a paste, applying the paste onto any sheet, and (ii) drying the paste.

[0091] In this embodiment, the adhesive layer 44 attaches the resin layer 42 to the surface of the FS of the steel plate 12. The adhesive layer 44 may be a layer of any type of adhesive material, and may be a commercially available adhesive tape or double-sided tape. This shortens the preparation time for the object 10 to be cut.

[0092] 5, the object 10 is different from the object 10 described in relation to FIGS. 2 and 3 in that the carbon supply layer 14 includes a solid carbon layer 52 and an adhesive layer 44. An adhesive layer may be used instead of the adhesive layer 44. With respect to features other than the above differences, the object 10 in FIG. 5 may have the same configuration as the object 10 described in relation to FIGS. 2 and 3.

[0093] 5, the object 10 differs from the object 10 described in relation to FIG. 4 in that the carbon supply layer 14 includes a solid carbon layer 52 instead of the resin layer 42. An adhesive layer may be used instead of the adhesive layer 44. With respect to features other than the above differences, the object 10 in FIG. 5 may have the same configuration as the object 10 described in relation to FIG. 4.

[0094] Examples of the solid carbon layer 52 include carbon fiber, carbon film, and carbon powder. For example, first, an adhesive layer 44 is disposed on the FS side surface of the steel plate 12. For example, the adhesive layer 44 is attached to the FS side surface of the steel plate 12 so that one surface of the adhesive layer 44 faces the FS side surface of the steel plate 12. Next, solid carbon such as carbon fiber, carbon film, and carbon powder is disposed on the other surface of the adhesive layer 44. Next, the solid carbon is pressed, and attached to the FS side surface of the steel plate 12 via the adhesive layer 44.

[0095] 6 shows an example of the internal configuration of the controller 180. In this embodiment, the controller 180 includes, for example, a cutting condition determination unit 620 and a cutting condition adjustment unit 640. In this embodiment, the cutting condition determination unit 620 includes, for example, a gas flow rate determination unit 622, a nozzle distance determination unit 624, a cutting width determination unit 626, and a cutting speed determination unit 628. In this embodiment, the cutting condition adjustment unit 640 includes, for example, a gas flow rate adjustment unit 642, a nozzle distance adjustment unit 644, a cutting width adjustment unit 646, and a cutting speed adjustment unit 648.

[0096] In this embodiment, the cutting condition determination unit 620 determines the cutting conditions. The cutting condition determination unit 620 may determine the cutting conditions based on information input by the user to the input / output device 170. Examples of the cutting conditions include (i) the flow rate of the fuel gas supplied to the gas burner 110, (ii) the flow rate of the oxygen-containing gas supplied to the gas burner 110, (iii) the relative distance between the gas burner 110 and the surface of the workpiece 10 (i.e., the nozzle distance), (iv) the moving speed of the gas burner 110, and (v) the cutting width Wc. In addition, when a solid or liquid carbon-containing material is continuously or intermittently supplied during cutting of the steel plate 12, the supply amount of the carbon-containing material may be an example of the cutting conditions.

[0097] In one embodiment, a set value for at least one of (i) the flow rate of the fuel gas supplied to the gas burner 110, (ii) the flow rate of the oxygen-containing gas supplied to the gas burner 110, (iii) the relative distance between the gas burner 110 and the surface of the workpiece 10 (i.e., the nozzle distance), (iv) the moving speed of the gas burner 110, and (v) the width Wc of the cutting region 200 is input to the input / output device 170. In this case, the cutting condition determination unit 620 uses the set value input to the input / output device 170 as at least a part of the above-mentioned cutting conditions. The above-mentioned set value may be determined based on the ratio of the mass of carbon contained in the carbon supply layer 14 arranged in the cutting region 200 to the mass of the steel plate 12 arranged in the cutting region 200.

[0098] In another embodiment, (i) information on the mass of carbon contained in the carbon supply layer 14 arranged in the cutting region 200, and (ii) information on the mass of the steel plate 12 arranged in the cutting region 200 are input to the input / output device 170. In this case, the cutting condition determination unit 620 determines at least a part of the above-mentioned cutting conditions based on the ratio of the mass of carbon contained in the carbon supply layer 14 arranged in the cutting region 200 to the mass of the steel plate 12 arranged in the cutting region 200.

[0099] Examples of the information on the mass of carbon contained in the carbon supply layer 14 arranged in the cutting region 200 include the carbon content of the carbon supply layer 14 [kg-c / kg-carbon supply layer 14] and the thickness Ha [m] of the carbon supply layer 14. Examples of the information on the mass of the steel plate 12 arranged in the cutting region 200 include the density of the steel plate 12 [kg-steel plate 12 / m 3 -steel plate 12], and the thickness Hm [m] of steel plate 12 are examples.

[0100] For example, the cutting condition determination unit 620 determines the flow rate of the oxygen-containing gas based on the mass ratio of carbon. When the oxygen supply system 140 includes an oxygen gas source and an inert gas source, the cutting condition determination unit 620 may determine the supply amount of at least one of the oxygen gas and the inert gas based on the mass ratio of carbon.

[0101] For example, the cutting condition determination unit 620 estimates the viscosity of the molten steel sheet 12 from the mass ratio of carbon, and determines the flow rate of the oxygen-containing gas based on the estimated viscosity. The cutting condition determination unit 620 may estimate the viscosity of the molten steel sheet 12 using a function in which the mass ratio of carbon to the mass of the steel sheet 12 is an explanatory variable and the viscosity of the molten steel sheet 12 is an objective function. The cutting condition determination unit 620 may estimate the viscosity of the molten steel sheet 12 using a viscosity estimation model generated by machine learning for estimating the viscosity of the molten steel sheet 12 from the mass ratio of carbon to the mass of the steel sheet 12. The cutting condition determination unit 620 may determine the flow rate of the oxygen-containing gas using a flow rate estimation model generated by machine learning for estimating the flow rate of the oxygen-containing gas from the mass ratio of carbon to the mass of the steel sheet 12.

[0102] In another embodiment, information indicating the thickness Hm [m] of the steel plate 12 and information indicating the thickness Ha [m] of the carbon supply layer 14 are input to the input / output device 170. In this case, the cutting condition determination unit 620 determines the nozzle distance based on the sum of the thickness Hm [m] of the steel plate 12 and the thickness Ha [m] of the carbon supply layer 14. For example, the nozzle distance is determined to be greater than the sum of the thickness Hm [m] of the steel plate 12 and the thickness Ha [m] of the carbon supply layer 14.

[0103] In another embodiment, the cutting condition determination unit 620 analyzes the image data output by the camera 160 to determine at least a part of the above-mentioned cutting conditions. For example, the cutting condition determination unit 620 analyzes an image of the BS side of the steel plate 12 to estimate the flow state of the molten material of the steel plate 12. Examples of the flow state of the molten material include (i) a state in which the fluidity is low and the amount or speed of the slag of the molten material adhering to the BS of the steel plate 12 is greater than a predetermined value, (ii) a state in which the fluidity is high and the amount or speed of the slag of the molten material adhering to the BS of the steel plate 12 is smaller than a predetermined value, (iii) a state in which the fluidity is high and the discharge state of the molten material from the BS of the steel plate 12 is good, and (iv) a state in which the fluidity is high and the molten material drips from the BS of the steel plate 12 by its own weight.

[0104] The cutting condition determination unit 620 determines at least a part of the above-mentioned cutting conditions based on the estimated fluidity state of the molten material. For example, when the fluidity of the molten material is low, the cutting condition determination unit 620 determines to (i) increase the gas flow rate of the oxygen-containing gas and / or (ii) decrease the nozzle distance. This increases the amount of molten material discharged from the steel plate 12 even when the fluidity of the molten material is relatively low. As a result, the amount of slag adhering to the steel plate 12 decreases. When the fluidity of the molten material is low, the cutting condition determination unit 620 may increase the gas flow rate of the fuel gas. This increases the temperature of the molten material and decreases the viscosity of the molten material. As a result, the amount of molten material discharged from the steel plate 12 increases or the amount of slag adhering to the steel plate 12 decreases.

[0105] The cutting condition determination unit 620 may determine to increase or decrease at least one of the flow rate of the oxygen-containing gas, the nozzle distance, and the supply amount of the carbon-containing material so that the discharge state of the molten material from the BS of the steel sheet 12 becomes a predetermined state. The cutting condition determination unit 620 may also determine to increase or decrease at least one of the flow rate of the oxygen-containing gas, the nozzle distance, and the supply amount of the carbon-containing material so that the adhesion state of the slag of the molten material at the BS of the steel sheet 12 becomes a predetermined state. This can suppress the adhesion of the slag of the molten material at the BS of the steel sheet 12.

[0106] In this embodiment, the gas flow rate determination unit 622 determines the flow rate of at least one of the oxygen-containing gas and the fuel gas by the above-mentioned method. In this embodiment, the nozzle distance determination unit 624 determines the nozzle distance by the above-mentioned method.

[0107] In this embodiment, the cutting width determination unit 626 determines the cutting width Wc. For example, the cutting width determination unit 626 determines the cutting width Wc based on a setting value for the cutting width Wc input to the input / output device 170 by the user.

[0108] In this embodiment, the cutting speed determination unit 628 determines the cutting speed by the above-described method. For example, the cutting speed determination unit 628 determines the cutting speed based on a setting value related to the cutting speed input by the user to the input / output device 170.

[0109] In this embodiment, the cutting condition adjustment unit 640 adjusts various setting values ​​related to at least one of the burner support unit 122, the transfer unit 124, the oxygen supply system 140, and the fuel supply system 150 based on the cutting conditions determined by the cutting condition determination unit 620. The cutting condition adjustment unit 640 may output a control signal for controlling the operation of at least one of the burner support unit 122, the transfer unit 124, the oxygen supply system 140, and the fuel supply system 150.

[0110] In this embodiment, the gas flow rate adjusting unit 642 generates a control signal indicating the gas flow rate of the oxygen-containing gas determined by the gas flow rate determining unit 622. The gas flow rate adjusting unit 642 outputs the control signal to the oxygen supply system 140. This causes the gas flow rate of the oxygen-containing gas to be adjusted.

[0111] The gas flow rate adjusting unit 642 generates a control signal indicating the gas flow rate of the fuel gas determined by the gas flow rate determining unit 622. The gas flow rate adjusting unit 642 outputs the control signal to the fuel supply system 150. In this way, the gas flow rate of the fuel gas is adjusted.

[0112] In this embodiment, the nozzle distance adjustment unit 644 generates a control signal indicating the nozzle distance determined by the nozzle distance determination unit 624. The nozzle distance adjustment unit 644 outputs the above control signal to the burner support unit 122. This adjusts the nozzle distance.

[0113] In this embodiment, the cutting width adjustment unit 646 generates a control signal indicating the cutting width determined by the cutting width determination unit 626. The cutting width adjustment unit 646 outputs the above control signal to, for example, the gas burner 110. This adjusts the aperture or flame diameter of the cutting tip 112, and as a result, the cutting width is adjusted.

[0114] In this embodiment, the cutting speed adjusting unit 648 generates a control signal indicating the cutting speed determined by the cutting speed determining unit 628. The cutting speed adjusting unit 648 outputs the control signal to the transport unit 124. This adjusts the transport speed of the gas burner 110, and as a result, the cutting speed is adjusted.

[0115] The disconnection condition determination unit 620 may be an example of a control unit. The disconnection condition determination unit 620 may be an example of a first determination unit or a second determination unit.

[0116] FIG. 7 shows an example of a cutting method using the gas cutting system 100. According to this embodiment, first, in step 722 (the step may be abbreviated to S), the object 10 to be cut is prepared. Specifically, the carbon supply layer 14 is arranged on the surface of the cutting region 200 of the steel plate 12. For example, a carbon paste obtained by mixing a solid carbon source 22 and a binder resin 24 with a solvent is applied to the surface of the cutting region 200 of the steel plate 12. At this time, a preheating region 300 where the carbon paste is not applied is formed on the surface of the cutting region 200 of the steel plate 12. Thereafter, the carbon paste is dried to form the carbon supply layer 14 on the surface of the steel plate 12.

[0117] Next, in S724, the workpiece 10 is placed in the gas cutting system 100. Specifically, the workpiece 10 is placed in a predetermined position on the table 132.

[0118] Next, in S726, the cutting conditions of the gas cutting system 100 are determined. According to one embodiment, a user determines the cutting conditions of the gas cutting system 100 and inputs information indicating the cutting conditions to the input / output device 170. According to another embodiment, a user inputs information used to determine the cutting conditions of the gas cutting system 100 to the input / output device 170, and the controller 180 determines the cutting conditions of the gas cutting system 100.

[0119] Next, in S728, the cutting conditions of the gas cutting system 100 are adjusted. For example, the controller 180 generates a control signal indicating the setting value of each part of the gas cutting system 100. The controller 180 outputs the above control signal to each part of the gas cutting system 100, thereby adjusting the cutting conditions of the gas cutting system 100.

[0120] Thereafter, in S730, the gas cutting system 100 gas cuts the workpiece 10. As a result, the member 32 and the member 34 are produced.

[0121] Specifically, the gas cutting system 100 first supplies fuel gas and oxygen-containing gas for preheating to the gas burner 110 and ignites the fuel gas. The gas cutting system 100 heats the preheating region 300 of the workpiece 10 with a flame ejected from the gas burner 110. Thereafter, the gas cutting system 100 supplies oxygen-containing gas for gas cutting to the gas burner 110 and starts gas cutting of the workpiece 10.

[0122] As described above, the workpiece 10 includes the steel plate 12 and the carbon supply layer 14 disposed on the FS side surface of the steel plate 12. Therefore, when the gas cutting system 100 heats the cutting region 200 of the steel plate 12, the steel plate 12 and the carbon supply layer 14 are heated, and the cutting region 200 of the steel plate 12 melts. At this time, the cutting region 200 of the steel plate 12 melts in a state in which carbon contained in the carbon supply layer 14 is supplied.

[0123] As described above, the carbon content of the carbon supply layer 14 is adjusted so that the mass of carbon contained in the molten steel plate 12 is 0.45 mass % or more and 10 mass % or less of the mass of the molten steel plate 12. This reduces the viscosity of the molten steel plate 12 compared to a case where the carbon supply layer 14 is not provided on the surface of the steel plate 12. In this state, the molten steel plate 12 is blown away by the oxygen gas ejected from the gas cutting system 100, and the steel plate 12 is cut.

[0124] [An example of another embodiment] In this embodiment, the details of the gas cutting system 100 have been described by taking as an example a case where the gas cutting system 100 gas-cuts the workpiece 10. That is, the details of the gas cutting system 100 have been described by taking as an example a case where the gas cutting system 100 heats a cutting region of a metal material and supplies an oxygen-containing gas to the heated metal material, thereby melting the cutting region of the metal material. However, the gas cutting system 100 is not limited to this embodiment.

[0125] In another embodiment, the gas cutting system 100 may cut the workpiece 10 by arc cutting (sometimes referred to as plasma cutting). In this case, the gas cutting system 100 melts the cutting area of ​​the metal material by heating the cutting area of ​​the metal material with an electric arc or a plasma arc. In yet another embodiment, the gas cutting system 100 may cut the workpiece 10 by laser cutting. In this case, the gas cutting system 100 melts the cutting area of ​​the metal material by heating the cutting area of ​​the metal material with a laser beam.

[0126] In the present embodiment, the details of the gas cutting system 100 have been described by taking as an example a case in which the gas cutting system 100 cuts the workpiece 10 including a single metal material. However, the gas cutting system 100 is not limited to the present embodiment.

[0127] In another embodiment, the workpiece 10 may include a plurality of metal materials. In one embodiment, the workpiece 10 includes a structure in which a plurality of metal plates are stacked. At least two of the plurality of metal plates may be made of the same metal material, or at least two of the plurality of metal plates may be made of different types of metal materials. In another embodiment, the workpiece 10 includes an assembly of a plurality of metal blocks. At least two of the plurality of metal blocks may be made of the same metal material, or at least two of the plurality of metal blocks may be made of different types of metal materials. Details of the metal materials may be as described above.

[0128] In this embodiment, the details of the gas cutting system 100 have been described by taking as an example a case in which carbon is used as a substance that reduces the viscosity of the molten steel plate 12. However, the gas cutting system 100 is not limited to this embodiment.

[0129] In another embodiment, a substance containing silicon or aluminum is used as a substance that reduces the viscosity of the molten steel sheet 12 containing iron or an iron alloy. For example, an oxide of silicon or aluminum is used. For example, Non-Patent Document 1 discloses that the viscosity of the molten Fe-Si alloy is reduced by adding 2, 5, or 10 mass% of metallic silicon to electrolytic iron. Therefore, by melting the cutting region 200 of the steel sheet 12 in a state in which 2 to 10 mass% (preferably 5 to 10 mass%) of silicon is supplied with respect to the mass of the steel sheet 12 instead of the carbon contained in the carbon supply layer 14, the amount of slag adhering to the BS side of the steel sheet 12 can be reduced. Note that when carbon is used as a substance that reduces the viscosity of the molten steel sheet 12, the viscosity of the molten steel sheet 12 can be reduced more easily than when silicon is used as a substance that reduces the viscosity of the molten steel sheet 12.

[0130] In yet another embodiment, when the gas cutting system 100 cuts a workpiece 10 that includes aluminum or an aluminum alloy, examples of substances that reduce the viscosity of the molten aluminum include silicon, silicon oxide, alumina, aluminum fluoride, etc., as described above.

[0131] 8 shows an example of a computer 3000 in which aspects of the present invention may be embodied in whole or in part. For example, a part of the gas cutting system 100 is realized by the computer 3000. More specifically, for example, at least a part of the controller 180 is realized by the computer 3000.

[0132] A program installed on the computer 3000 may cause the computer 3000 to function as or perform operations associated with an apparatus according to an embodiment of the present invention or one or more "parts" of the apparatus, and / or to perform a process or steps of the process according to an embodiment of the present invention. Such a program may be executed by the CPU 3012 to cause the computer 3000 to perform certain operations associated with some or all of the blocks of the flowcharts and block diagrams described herein.

[0133] The computer 3000 according to this embodiment includes a CPU 3012, a RAM 3014, a GPU 3016, and a display device 3018, which are connected to each other by a host controller 3010. The computer 3000 also includes input / output units such as a communication interface 3022, a hard disk drive 3024, a DVD-ROM drive 3026, and an IC card drive, which are connected to the host controller 3010 via an input / output controller 3020. The computer also includes legacy input / output units such as a ROM 3030 and a keyboard 3042, which are connected to the input / output controller 3020 via an input / output chip 3040.

[0134] The CPU 3012 operates according to a program stored in the ROM 3030 and the RAM 3014, thereby controlling each unit. The GPU 3016 acquires image data generated by the CPU 3012 into a frame buffer or the like provided in the RAM 3014 or into the GPU 3016 itself, and causes the image data to be displayed on the display device 3018.

[0135] The communications interface 3022 communicates with other electronic devices via a network. The hard disk drive 3024 stores programs and data used by the CPU 3012 in the computer 3000. The DVD-ROM drive 3026 reads programs or data from the DVD-ROM 3001 and provides the programs or data to the hard disk drive 3024 via the RAM 3014. The IC card drive reads programs and data from an IC card and / or writes programs and data to an IC card.

[0136] The ROM 3030 stores therein a boot program or the like executed by the computer 3000 upon activation, and / or a program that depends on the hardware of the computer 3000. The input / output chip 3040 may also connect various input / output units to the input / output controller 3020 via a parallel port, a serial port, a keyboard port, a mouse port, etc.

[0137] The programs are provided by a computer-readable storage medium such as a DVD-ROM 3001 or an IC card. The programs are read from the computer-readable storage medium, installed in the hard disk drive 3024, the RAM 3014, or the ROM 3030, which are also examples of computer-readable storage media, and executed by the CPU 3012. Information processing described in these programs is read by the computer 3000, and brings about cooperation between the programs and the various types of hardware resources described above. An apparatus or method may be constructed by realizing an operation or processing of information according to the use of the computer 3000.

[0138] For example, when communication is performed between computer 3000 and an external device, CPU 3012 may execute a communication program loaded in RAM 3014 and instruct communication interface 3022 to perform communication processing based on the processing described in the communication program. Under the control of CPU 3012, communication interface 3022 reads transmission data stored in a transmission buffer area provided in RAM 3014, hard disk drive 3024, DVD-ROM 3001, or a recording medium such as an IC card, and transmits the read transmission data to the network, or writes reception data received from the network to a reception buffer area or the like provided on the recording medium.

[0139] Furthermore, CPU 3012 may cause all or a necessary portion of a file or database stored in an external recording medium such as hard disk drive 3024, DVD-ROM drive 3026 (DVD-ROM 3001), an IC card, etc. to be read into RAM 3014, and perform various types of processing on the data on RAM 3014. CPU 3012 may then write back the processed data to the external recording medium.

[0140] Various types of information, such as various types of programs, data, tables, and databases, may be stored in the recording medium and undergo information processing. The CPU 3012 may perform various types of processing on the data read from the RAM 3014, including various types of operations, information processing, conditional judgment, conditional branching, unconditional branching, information search / replacement, etc., as described throughout this disclosure and specified by the instruction sequence of the program, and writes back the results to the RAM 3014. The CPU 3012 may also search for information in a file, database, etc. in the recording medium. For example, when a plurality of entries each having an attribute value of a first attribute associated with an attribute value of a second attribute are stored in the recording medium, the CPU 3012 may search for an entry whose attribute value of the first attribute matches a specified condition from among the plurality of entries, read the attribute value of the second attribute stored in the entry, and thereby obtain the attribute value of the second attribute associated with the first attribute that satisfies a predetermined condition.

[0141] The above-described programs or software modules may be stored in a computer-readable storage medium on the computer 3000 or in the vicinity of the computer 3000. In addition, a recording medium such as a hard disk or a RAM provided in a server system connected to a dedicated communication network or the Internet can be used as a computer-readable storage medium, thereby providing the above-described programs to the computer 3000 via the network.

[0142] The blocks in the flowcharts and block diagrams in the above embodiments may represent stages of a process in which an operation is performed or "parts" of an apparatus responsible for performing the operation. Particular stages and "parts" may be implemented by dedicated circuitry, programmable circuitry provided with computer readable instructions stored on a computer readable storage medium, and / or a processor provided with computer readable instructions stored on a computer readable storage medium. The dedicated circuitry may include digital and / or analog hardware circuits, and may include integrated circuits (ICs) and / or discrete circuits. The programmable circuitry may include reconfigurable hardware circuits, such as, for example, field programmable gate arrays (FPGAs), programmable logic arrays (PLAs), and the like, including AND, OR, XOR, NAND, NOR, and other logical operations, flip-flops, registers, and memory elements.

[0143] A computer-readable storage medium may include any tangible device capable of storing instructions that are executed by a suitable device, such that a computer-readable storage medium having instructions stored thereon comprises an article of manufacture that includes instructions that can be executed to create means for performing the operations specified in the flowcharts or block diagrams. Examples of computer-readable storage media may include electronic storage media, magnetic storage media, optical storage media, electromagnetic storage media, semiconductor storage media, and the like. More specific examples of computer-readable storage media may include floppy disks, diskettes, hard disks, random access memories (RAMs), read-only memories (ROMs), erasable programmable read-only memories (EPROMs or flash memories), electrically erasable programmable read-only memories (EEPROMs), static random access memories (SRAMs), compact disk read-only memories (CD-ROMs), digital versatile disks (DVDs), Blu-ray disks, memory sticks, integrated circuit cards, and the like.

[0144] The computer readable instructions may include either assembler instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state-setting data, or source or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk, JAVA, C++, etc., and conventional procedural programming languages ​​such as the "C" programming language or similar programming languages.

[0145] Computer readable instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus, or to a programmable circuit, either locally or over a local area network (LAN), a wide area network (WAN), such as the Internet, etc., to cause the processor of the general purpose computer, special purpose computer, or other programmable data processing apparatus, or to a programmable circuit, to execute the computer readable instructions to generate means for performing the operations specified in the flowcharts or block diagrams. Examples of processors include computer processors, processing units, microprocessors, digital signal processors, controllers, microcontrollers, etc.

[0146] Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It is clear to those skilled in the art that various modifications or improvements can be made to the above embodiments. In addition, the matters described for a specific embodiment can be applied to other embodiments to the extent that they are not technically inconsistent. It is clear from the claims that such modified or improved forms can also be included in the technical scope of the present invention.

[0147] It should be noted that the order of execution of each process, such as operations, procedures, steps, and stages, in the devices, systems, programs, and methods shown in the claims, specifications, and drawings is not specifically stated as "before," "prior to," etc., and may be realized in any order unless the output of a previous process is used in a later process. Even if the operational flow in the claims, specifications, and drawings is explained using "first," "next," etc. for convenience, it does not mean that it is essential to perform the process in this order. EXAMPLES

[0148] The details of the method for cutting the workpiece 10 by the gas cutting system 100 will be described using examples, comparative examples, and reference examples. Note that the method for cutting the workpiece 10 by the gas cutting system 100 is not limited to the following examples, comparative examples, and reference examples.

[0149] [Example 1] A portable automatic gas cutting machine (KT-160N II) manufactured by Nippon Sanso Tanaka Co., Ltd. was used to cut a steel plate of SS400 (sometimes referred to as a cutting specimen). In Example 1, a cut specimen having a carbon layer on one side of the steel plate of SS400 was used.

[0150] (Preparation of sample pieces for cutting) To prepare a sample piece for the cutting test, first, SS400, which is commercially available as a rolled steel material for general construction, was cut to a specified size to prepare a steel plate of SS400. The size of the steel plate of SS400 was 80 mm wide, 150 mm long, and 70 mm thick. The composition of elements other than iron contained in SS400 was C = 0.19 mass%, Si = 0.25 mass%, Mn = 0.83 mass%, P = 0.11 mass%, and S = 0.03 mass%. The contents of Cu, Ni, and Cr were below the measurement limit. The black scale on the surface of the steel material was not removed.

[0151] Next, activated carbon powder (Artec Co., Ltd., 055827) and cyanoacrylate (Toa Gosei Co., Ltd., 05501) diluted with acetone (Wako Pure Chemical Industries, Ltd., 013-00356) were mixed in a mass ratio of 2:1 to prepare a carbon paste. The average particle size of the activated carbon powder determined by a sieving test was 1 mm. The sieving test was performed in accordance with JIS Z8815-1994. The mass ratio of acetone to cyanoacrylate was 12:1.

[0152] Next, carbon paste was applied to one side of the cut SS400 steel plate, and the carbon paste was dried to prepare a carbon layer. The carbon paste was applied so that a carbon layer would not be formed at the position where gas cutting of the SS400 steel plate was to begin. The size of the carbon layer was 5 mm wide, 130 to 140 mm long, and 5 mm thick. The area where the carbon layer was not formed was used as a preheating area. In this way, a cutting sample piece was prepared. The ratio of the mass of the activated carbon powder contained in the carbon layer having a width of 5 mm, a thickness of 5 mm, and a unit length to the mass of the steel plate having a width of 5 mm, a thickness of 70 mm, and a unit length was about 1 mass%.

[0153] (Gas cutting machine settings) The fuel gas used was LP gas (PP, manufactured by Shikoku Taiyo Nippon Sanso Co., Ltd.). The composition of the LP gas was C 3 H 8 = 97.3 mol%, C 2 H 6 = 1.60 mol%, iC 4 H 10 = 0.90 mol%, C 3 H 6 = 0.10 mol%, nC 4 H 10 =0.10mol%. Oxygen gas (Kitajima Oxygen Co., Ltd., gaseous oxygen 99.5% or more) was used as the oxygen-containing gas. Fuel gas was supplied from a nozzle placed on the outside of the gas burner, and oxygen gas was supplied from a nozzle placed on the inside of the gas burner. Therefore, the temperature of the center of the flame was higher than the temperature of the outside of the flame.

[0154] (Preheating treatment) First, the specimen was set in the gas cutting machine so that the side of the specimen on which the carbon layer was arranged (sometimes referred to as FS) was facing up. The specimen was set so that the side of the specimen on which the carbon layer was arranged faced the nozzle of the gas burner. Next, LP gas was supplied to the gas burner of the gas cutting machine, and the preheating area of ​​the specimen was heated by the flame of the LP gas alone. It was visually confirmed that the steel plate surface of the specimen turned bright red, and it was determined that the preheating process was complete. At this time, the temperature of the steel plate was estimated to be about 1100K.

[0155] (Disconnection process) After the preheating of the cutting sample was completed, oxygen gas was supplied to the gas burner of the gas cutting machine and the cutting process was started. During the cutting process, the fuel gas pressure was set to 0.04 MPa, and the oxygen gas pressure was set to 0.3 MPa. The total pressure of the fuel gas and oxygen gas was 0.34 MPa. The diameter of the oxygen jet (i.e., the cutting width) was 5 mm, and the flame length was about 100 mm.

[0156] Next, the nozzle distance was set to 10 mm, and the cutting speed was set to 100 mm / min. Then, the automatic feed switch of the gas cutting machine was turned on. This caused the cutting position to move along the length of the sample piece to be cut, and the cutting process was started. Then, it was confirmed that the sample piece to be cut was cut over its entire length, and the cutting process was terminated. Note that one of the two pieces of the sample piece to be cut may be called the base material, and the other may be called the slice.

[0157] [Comparative Example 1] The preheating treatment and cutting treatment were carried out in the same manner as in Example 1, except that a SS400 steel plate having no carbon layer was used as the cutting sample.

[0158] [Reference example 1] Except for the fact that a steel plate of S48C (manufactured by JFE Steel Corporation, carbon steel material for machine structures S48C, JIS G4051:2016) without a carbon layer was used as the cutting sample, preheating treatment and cutting treatment were performed in the same manner as in Example 1. The composition of elements other than iron contained in S48C was C = 0.47 mass%, Si = 0.20 mass%, Mn = 0.66 mass%, P = 0.08 mass%, S = 0.03 mass%, Cu = 0.04 mass%, Ni = 0.02 mass%, and Cr = 0.02 mass%.

[0159] [Reference example 2] The preheating treatment and cutting treatment were carried out in the same manner as in Example 1, except that the oxygen gas pressure was changed to 0.4 to 0.8 MPa.

[0160] [evaluation] (Behavior of molten material and slag during gas cutting) A high-speed camera (manufactured by Shodensha Co., Ltd., CH130EX, number of pixels: 1280 × 1024 pixels, 200 fps) was used to capture images of the appearance of the side opposite the FS of the cutting specimen (sometimes called the BS) during gas cutting. An interference filter that blocks light with wavelengths other than 800 to 1000 nm (near-infrared light) was attached to the lens of the high-speed camera. This allowed observation of the state of combustion during gas cutting and the behavior of the slag on the BS side of the cutting specimen.

[0161] (Volume of slag attached to steel plate) The appearance of the cut specimen after gas cutting was photographed using a digital camera (Casio Computer Co., Ltd., EX-ZR1600). In addition, the height and width of the slag attached to the BS side of the cut specimen were measured using a steel ruler at 15 positions at 10 mm intervals from the cutting start position along the length of the cut specimen. The height H S1 [mm] and width W S1 [mm] and the height H of the slag attached to the BS side of the base material S2 [mm] and width W S2 The volume per 10 mm of length was calculated using the values ​​of [mm] and the amount of slag attached at each position [mm3 More specifically, the above volume is (H S1 +H S2 ) / 2×(W S1 +W S2 ) × 10.

[0162] (Slag removability) Using a chisel and a hammer, it was confirmed whether or not the slag adhering to the BS side of the cutting sample piece could be peeled off by manual force.

[0163] (residual carbon in slag) The residual carbon concentration in the slag was measured using a carbon analyzer (EMIA-Pro, manufactured by Horiba, Ltd.) and an X-ray diffraction device (RINT-Ultima III, manufactured by Rigaku Corporation). The X-ray diffraction measurement was performed under the condition of 40 kV / 30 mA. (i) The slag attached to the steel plate base material of the cutting specimen, (ii) the slag attached to the slice, and (iii) the slag dropped from the cutting specimen were each powdered to prepare samples for measurement. For each of Example 1, Comparative Example 1, and Reference Example 1, two samples taken from two locations of the slag attached to the base material, two samples taken from two locations of the slag attached to the slice, and two samples taken from two locations of the dropped slag were prepared as samples for measurement. In addition, for comparison, a sample obtained by scraping off a part of the SS400 steel material and a sample obtained by scraping off a part of the S48C steel material were prepared.

[0164] [Evaluation Results] (Slag behavior during gas cutting) The behavior of the molten material and slag during gas cutting is shown using Figures 9, 10 and 11. Image 900 in Figure 9 shows how slag is discharged from the back surface of the workpiece in Example 1. Image 1000 in Figure 10 shows how slag is discharged from the back surface of the workpiece in Comparative Example 1. Image 1100 in Figure 11 shows how slag is discharged from the back surface of the workpiece in Reference Example 1. Note that in Reference Example 2, the slag was blown away and did not adhere to the BS of the sample piece to be cut.

[0165] As shown in image 900 of Fig. 9, in Example 1, the molten metal (indicated as Slag (Liquid) in the figure) was forcefully discharged from the BS of the sample piece to be cut (indicated as Workpiece in the figure). In addition, a part of the molten metal (sometimes called slag) (indicated as Slag (Solid) in the figure) was fixed to the BS of the sample piece to be cut.

[0166] 10, in Comparative Example 1, as the cutting progressed, the molten metal remained on the BS of the cutting specimen, formed a large lump, and then dripped down under its own weight. Also, some of the slag was attached to the BS of the cutting specimen.

[0167] As shown in the image 1100 of Fig. 11, the molten metal appropriately dripped from the BS of the cutting sample piece in Reference Example 1. In addition, almost no slag was found remaining on the BS of the cutting sample piece.

[0168] (Volume of slag attached to steel plate) FIG. 12 shows the volume of sludge adhering to the back surface of the workpiece. In Example 1, the height of the slug at each position was 5 to 7 mm. The width of the slug at each position was 12 to 20 mm. In Comparative Example 1, the height of the slug at each position was 7 to 10 mm. The width of the slug at each position was 13 to 15 mm.

[0169] 12, the amount of slag adhesion in Example 1 was smaller than the amount of slag adhesion in Comparative Example 1. The average amount of slag adhesion in Example 1 was 8.8×10 2 [mm 3 The average amount of slag attached in Comparative Example 1 was 1.2 × 10 3 [mm 3 The average amount of slag attached in Reference Example 1 was 2.3 × 10 2 [mm 3 ] was the case.

[0170] In Example 1, the total volume of the slag attached to the BS of the cutting test piece was 1.3 × 10 4 [mm 3 In Comparative Example 1, the total volume of slag attached to the BS of the cutting test piece was 1.8 × 10 4 [mm 3 In Reference Example 1, the total volume of the slag adhering to the BS of the cutting test piece was 3.5 × 10 3 [mm 3 The total amount of slag generated was 52,500 [mm], cutting width 5 mm x length 150 mm x thickness 70 mm. 3 ], so that the slag adhesion rate relative to the total amount of slag generated was 25% in Example 1, 34% in Comparative Example 1, and 6.6% in Reference Example 1.

[0171] As described above, the amount of slag adhesion in Example 1 was reduced by about 30% compared to the amount of slag adhesion in Comparative Example 1. Furthermore, in cutting low carbon steel, the effect of suppressing slag adhesion by heating while supplying carbon or the like is particularly noticeable.

[0172] (Slag removability) In Example 1, 50 to 60% of the slag adhering to the back surface of the cutting specimen was removed by breaking the slag with a chisel and a hammer. In Comparative Example 1, 50 to 60% of the slag adhering to the back surface of the cutting specimen was removed by breaking the slag with a chisel and a hammer.

[0173] On the other hand, in Reference Example 1, about 20% of the slag adhering to the back surface of the cutting specimen could be removed by pressing with bare hands without using a chisel or a hammer. Moreover, by destroying the slag with a chisel and a hammer, all the remaining slag could be removed.

[0174] (residual carbon in slag) In Example 1, the average carbon concentration of the six samples was 0.01% by mass. In Comparative Example 1, the average carbon concentration of the six samples was 0.05% by mass. In Reference Example 1, the average carbon concentration of the six samples was 0.02% by mass. The carbon concentration of the SS400 sample was 0.19% by mass, which was within the range of the product specifications. The carbon concentration of the S48C sample was 0.51% by mass, which was within the range of the product specifications.

[0175] As a result of analyzing the X-ray diffraction spectrum of Example 1, it was found that FeO, Fe 3 O 4 and Fe 2 O 3 As a result of analyzing the X-ray diffraction spectrum of Comparative Example 1, the main peaks were FeO, Fe 3 O 4 and Fe 2 O 3 As a result of analyzing the X-ray diffraction spectrum of Reference Example 1, the following diffraction peaks were detected: FeO, Fe 3 O 4 and Fe 2 O 3 Diffraction peaks of the following were detected. [Explanation of symbols]

[0176] 10 workpiece, 12 steel plate, 14 carbon supply layer, 22 solid carbon source, 24 binder resin, 32 component, 34 component, 42 resin layer, 44 adhesive layer, 52 solid carbon layer, 100 gas cutting system, 110 gas burner, 112 cutting nozzle, 120 dolly, 122 burner support, 124 transport section, 130 stand, 132 table, 134 table, 136 support, 138 rail, 140 oxygen supply system, 142 piping, 144 oxygen-containing gas source, 146 pressure gauge, 147 mass flow controller, 148 valve, 150 fuel supply system, 152 piping, 154 fuel gas source, 156 pressure gauge, 157 mass flow controller, 158 valve, 160 camera, 170 input / output device, 180 Controller, 200 cutting area, 300 preheating area, 620 cutting condition determination unit, 622 gas flow rate determination unit, 624 nozzle distance determination unit, 626 cutting width determination unit, 628 cutting speed determination unit, 640 cutting condition adjustment unit, 642 gas flow rate adjustment unit, 644 nozzle distance adjustment unit, 646 cutting width adjustment unit, 648 cutting speed adjustment unit, 900 image, 1000 image, 1100 image, 3000 computer, 3001 DVD-ROM, 3010 host controller, 3012 CPU, 3014 RAM, 3016 GPU, 3018 display device, 3020 input / output controller, 3022 communication interface, 3024 hard disk drive, 3026 DVD-ROM drive, 3030 ROM, 3040 input / output chip, 3042 keyboard

Claims

1. A method for cutting a metal material made of a metal element or an alloy mainly composed of the metal element, comprising the steps of: The method includes a step of cutting the metal material by melting the cutting region of the metal material in a state in which a viscosity reducing substance that reduces the viscosity of the melt of the metal element is supplied to a surface of the cutting region of the metal material. The step of cutting the metal material includes: preparing a workpiece having the viscosity reducing substance disposed on the surface of the cutting region of the metal material; heating the cut area of ​​the metallic material and the viscosity reducing material disposed in the cut area to melt the cut area of ​​the metallic material; Including, the workpiece has a viscosity adjusting material disposed on the surface of the cutting region of the metal material, the viscosity adjusting material including the viscosity reducing substance and a binder; The viscosity reducing material comprises a powder, granule, rod, fiber or film carbon material; Cutting method.

2. The step of cutting the metal material includes: supplying the viscosity reducing substance to the surface of the metal material such that a ratio of the mass of the viscosity reducing substance supplied to the cutting region to a mass of the metal material disposed in the cutting region is 0.05 mass % or more and 10 mass % or less; Including, The cutting method according to claim 1 .

3. The step of cutting the metal material includes: supplying the viscosity reducing substance to the surface of the metal material such that a ratio of the mass of the viscosity reducing substance supplied to the cutting region to a mass of the metal material disposed in the cutting region is 0.1 mass % or more and 5 mass % or less; Including, The cutting method according to claim 1 or 2.

4. The viscosity reducing material comprises at least one element of carbon, silicon, and aluminum; The cutting method according to any one of claims 1 to 3.

5. The step of cutting the metal material includes: (i) heating the cutting region of the metallic material and supplying an oxygen-containing gas to the heated metallic material, thereby melting the cutting region of the metallic material; (ii) heating the cut area of ​​the metallic material by an electric or plasma arc, thereby melting the cut area of ​​the metallic material; and / or (iii) heating the cut area of ​​the metal material with a laser beam to melt the cut area of ​​the metal material; Including, The cutting method according to any one of claims 1 to 4.

6. The step of cutting the metal material includes: melting the metallic material such that a mass of the viscosity reducing substance contained in the molten metallic material is 0.45% by mass or more and 10% by mass or less of a mass of the molten metallic material; Including, The cutting method according to any one of claims 1 to 5.

7. The metal element is iron. The cutting method according to any one of claims 1 to 6.

8. The carbon content of the iron or the alloy mainly composed of iron contained in the metal material is 0.45 mass% or less. The cutting method according to claim 7.

9. A method for producing a metal component, comprising the steps of: cutting a metal material to produce said metal part; The step of producing the metal part includes a step of cutting the metal material by the cutting method according to any one of claims 1 to 8. Production method.

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